1. Field of the Invention
This invention is directed in general to controller systems including transmitters and/or receivers which operate on a coded signal and, in particular, to a controller system in which the transmitter and receiver are capable of selectively operating with one of a plurality of coded signals at a plurality of frequencies.
2. Prior Art
Transmitter-receiver controller systems (hereinafter transmitter-receiver systems) are widely used for remote control and/or actuation of devices or appliances such as garage door openers, gate openers, security systems, and the like. For example, most conventional garage door opener systems use a transmitter-receiver combination to selectively activate the drive source (i.e., motor) for opening or closing the door. The receiver is usually mounted adjacent to the motor and receives a coded signal (typically RF) from the transmitter. The transmitter is carried in the vehicle and selectively activated by a user to send the coded signal to open or close the garage door.
Different manufacturers of such transmitter-receiver systems normally utilize different code schemes for the coded signal and may also operate their products at different transmission frequencies within the allocated frequency range for this type of system. The code scheme typically includes two aspects: 1) a device code (equivalent to a device address) for the transmitter and receiver, and 2) a transmission format, i.e., the characteristics of the transmitted signal including timing parameters and modulation characteristics related to encoded data. The code scheme used by one manufacturer is usually incompatible with the code schemes of systems produced by other manufacturers. Currently available transmitter-receiver systems typically employ custom encoders and decoders to implement the code scheme. These encoders and decoders are fabricated with custom integrated circuits such as application-specific integrated circuits (ASICs). They are, to a large degree, fixed hardware devices and allow very limited flexibility in the encoding/decoding operation or in the modification of the encoding/decoding operation.
Consequently, if a user has two or more systems from different manufacturers, multiple transmitters may be necessary to operate all of the systems. For example, if a user has multiple garages (e.g., a vacation home, an office or the like), multiple transmitters may be required to operate different systems at each location. Moreover, businesses that sell or maintain transmitter-receiver systems from more than one manufacturer must maintain an inventory of each type of device when the transmitters/receivers have distinct code transmission format or transmission frequency requirements.
To provide greater flexibility and avoid the requirement for multiple inventories, there is a need for a transmitter unit and a receiver unit which can selectively emulate the transmitters and receivers of other transmitter-receiver systems to enable the transmitter unit and/or receiver unit to operate in such other systems.